Intel did a spectacularly poor job with the ecosystem around the memory cells. They made two plays, and both were flops.

1. “Optane” in DIMM form factor. This targeted (I think) two markets. First, use as slower but cheaper and higher density volatile RAM. There was actual demand — various caching workloads, for example, wanted hundreds of GB or even multiple TB in one server, and Optane was a route to get there. But the machines and DIMMs never really became available. Then there was the idea of using Optane DIMMs as persistent storage. This was always tricky because the DDR interface wasn’t meant for this, and Intel also seems to have a lot of legacy tech in the way (their caching system and memory controller) and, for whatever reason, they seem to be barely capable of improving their own technology. They had multiple serious false starts in the space (a power-supply-early-warning scheme using NMI or MCE to idle the system, a horrible platform-specific register to poke to ask the memory controller to kindly flush itself, and the stillborn PCOMMIT instruction).

2. Very nice NVMe devices. I think this was more of a failure of marketing. If they had marketed a line of SSDs that, coupled with an appropriate filesystem, could give 99% fsync latency of 5 microseconds and they had marketed this, I bet people would have paid. But they did nothing of the sort — instead they just threw around the term “Optane” inconsistently.

These days one could build a PCM-backed CXL-connected memory mapped drive, and the performance might be awesome. Heck, I bet it wouldn’t be too hard to get a GPU to stream weights directly off such a device at NVLink-like speeds. Maybe Intel should try it.